To achieve a drug delivery system combining the programmable long circulation and targeting ability, surface engineering nanoparticles (NPs), having a sandwich structure consisting of a long circulating outmost layer, a targeting middle layer and a hydrophobic innermost core were constructed by mixing a
matrix metalloproteinase MMP2 and MMP9-sensitive copolymers (
mPEG-Pep-PCL) and
folate receptor targeted copolymers (FA-PEG-PCL). Their physiochemical traits including morphology, particle size,
drug loading content, and in vitro release profiles were studied. In vitro studies validated that the inhibition efficiency of
tumor cells was effectively correlated with NP concentrations. Furthermore, The PEG layer would detach from the NPs due to the up-regulated extracellular MMP2 and MMP9 in
tumors, resulting in the exposure of
folate to enhance the cellular internalization via
folate receptor mediated endocytosis, which accelerated the release rate of
CPT in vivo. The antitumor efficacy,
tumor targeting ability and bio-distribution of the NPs were examined in a
B16 melanoma cells xenograft mouse model. These NPs showed improved
tumor target ability and enhanced aggregation of
camptothecin (
CPT) in
tumor site and prominent suppression of
tumor growth. Thus this
mPEG-Pep-PCL@FA-PEG-PCL core-shell structure NP could be a better candidate for the
tumor specific delivery of hydrophobic
drug.